1. Field of the Invention
This invention relates to charge coupled device (CCD) technology, and more particularly to a charge coupled device having high charge transfer efficiency at high frequencies, i.e. in the range from 1 to 250GHz.
2. Description of the Prior Art
A new class of monolithic semiconductor apparatus adapted for storing and sequentially transferring electronic signals representing information in the form of packets of excess minority carriers localized in artificially induced potential wells has been disclosed by W. S. Boyle and G. S. Smith, in an article entitled "Charge Coupled Semiconductor Devices," B.S.T.J. Vol. 49, No. 4, April, 1970, pp. 587-593, inclusive. Such apparatus comprises a metal-insulator-semiconductor (MIS) structure wherein a plurality of metal electrodes are disposed in a row over the insulator (dielectric) which in turn overlies and is contiguous with the surface of a semiconductor body. Sequential application of voltages from 1, 2, 3 or 4 phase clocks coupled to the metal electrodes induces potential wells at the interface of the oxide and semiconductor body which act to transfer the charge carriers along the structure in a predetermined direction.